1. Field of the Invention
The present invention relates to a method and an apparatus for manufacturing a brake, and a method and an apparatus for inspecting the brake, and more particularly, to an art for assembling a waterproof and dustproof boot to the brake, and an art for inspection.
2. Background Art
A hydraulic brake applies brake to a vehicle, by moving a brake pad when a piston slides in a cylinder. Recently, for preventing defective movements of the piston due to corrosion of a sliding face, the hydraulic brake is provided with a waterproof and dustproof boot for preventing intrusion of powder dust into a space between the piston and the cylinder.
For example, in Patent Document 1, there is disclosed a mold type dust boot provided with a ring for enhancing a fastening force with respect to a cylinder side. Moreover, in Patent Document 2, there is disclosed a mounting structure of a dust boot in which the dust boot can be easily mounted to a cylinder side, by providing a coil member in the dust boot by insert molding. Further, in Patent Document 3, there is disclosed an art for assembling a boot to a piston while an inner diameter of the boot is enlarged by a jig having a taper face, or an art for assembling the boot to the cylinder while an outer shape of the boot is diminished. Still further, in Patent Document 4, there is disclosed an art for assembling a waterproof and dustproof boot to a piston, while an inner diameter of the boot is enlarged by a slide block which is guided along a taper face to make a diameter enlarging movement.
In addition to the assembling methods disclosed in the above described Patent Documents, there are other assembling arts as described below. FIGS. 16 and 17 are views showing a method for assembling a waterproof and dustproof boot according to the conventional art. In the conventional art, a waterproof and dustproof boot mounting jig 1010 which includes a first jig 1011 for assembling an inner part of a waterproof and dustproof boot 1009 to a piston 1008, and a second jig 1012 for assembling an outer part of the boot 1009 to a cylinder body 1006, as shown in FIG. 16, has been used. The first jig 1011 is a jig which can move in an axial direction inside the second jig 1012, and can relatively move with respect to the second jig 1012. The first jig 1011 is urged upward by a spring (not shown) which is interposed between the first jig 1011 and the second jig 1012. The waterproof and dustproof boot mounting jig 1010 pushes up the waterproof and dustproof boot 1009, in a state where the boot is mounted thereon (S101 in FIG. 16). The waterproof and dustproof boot 1009 continues to be pushed up, until it is fitted to the cylinder body 1006 (S102 in FIG. 16). While the waterproof and dustproof boot 1009 continues to be pushed up, the first jig 1011 is brought into contact with the piston 1008 and its upward movement is stopped. However, the second jig 1012 continues to be pushed upward, while contracting the spring. By the way, in order that bellows of the waterproof and dustproof boot 1009 which is set between the cylinder body 1006 and the piston 1008 may not be inflated with air, the second jig 1012 is provided with an annular rib 1013 for pushing up the bellows. This annular rib 1013 keeps on moving upward having a lip part 1091 of the waterproof and dustproof boot 1009 interposed between the rib 1013 and the piston 1008. Finally, the lip part 1091 is firmly connected to the piston 1008 (S103 in FIG. 16). The waterproof and dustproof boot mounting jig 1010 continues to be pushed up, and the second jig 1012 pushes the outer part of the waterproof and dustproof boot 1009 to press it against the cylinder body 1006 (S104 in FIG. 17). On this occasion, the bellows come into a state caught between the rib 1013 and the cylinder body 106. When the second jig 1012 has completely finished pushing up the outer part of the waterproof and dustproof boot 1009, the assembly of the waterproof and dustproof boot 1009 is completed (S105 in FIG. 17).    [Patent Document 1] JP-A-2002-327849    [Patent Document 2] JP-A-2004-190841    [Patent Document 3] JP-A-06-238575    [Patent Document 4] JP-A-05-104347
In case of the conventional assembling arts as described above, the boot is liable to be damaged with a pushing motion or the like during the assembling work, and moreover, it is difficult to inspect air tightness of the boot.